A user terminal displays information inputted through an input device and information read through a memory device on the screen. Also, the user terminal may transmit the information to other terminal via a network (e.g., SMS and messages).
There may be a variety of methods for the user terminal to perform security processing of the information. For example, a password setting method for information allows a user to execute, access, or use the information (e.g., log-in, lock screen, and open file) when password authentication of the user succeeds. Also, in message communication between user terminals, a transmitting terminal encrypts and transmits a message, and a receiving terminal receives and decrypts the encrypted message.
However, the foregoing security processing method disallows the user to selectively set an object to be encrypted and encrypts the whole information at one time. For example, in the password setting method for information, when the set password is exposed, security is unlocked and the whole information is all exposed. Also, in the encryption method for message communication, a message service provider can see an encrypted message, and an encryption service is provided to all messages at one time.
On the other hand, SNS (e.g., twitter, facebook, and kakaotalk), SMS, and a messenger application on a user terminal processes messages containing various contents, and not only a user but also other user can see the messages by manipulating the application. Suppose a computer terminal or a smart terminal of user A is given as an example, A's coworker, friend, and family could see stored information by manipulating A's user terminal. Also, because servers for communication service and application service involved during message communication relay the message communication, each service provider could freely see messages of the user. Here, if the user performs encryption when inputting information, information security of the user may be enhanced as only the user can decode the password.